For centuries paper has been manufactured by screening pulp slurry (paper machine). Even today paper is typically manufactured in a pulp slurry method. Paper manufactured by a slurry method generally has a structure in which cellulose fibers derived from wood, for example, are interlocked and bonded in part by the cohesive force of hydrogen bonds.
Slurry methods are wet methods, however, require a large amount of water, require dewatering and drying after the paper is made, thus requiring significant energy and time. The water that is used must also be appropriately processed as waste water. The equipment used in pulp slurry methods also require large-scale utilities and infrastructure for water, power, and water treatment needs, and is therefore difficult to scale down.
From the perspectives of energy conservation and environmental protection, so-called dry methods that use no or substantially no water are desired as methods of making paper without using a wet slurry, and PTL 1, for example, describes a paper recycling system that defibrates and deinks paper used as the feedstock in a dry process, adds a small amount of water to increase paper strength, and forms paper.